Child safety seats are employed for safely transporting children in vehicles, in particular in cars. There is a large variety of child safety seats adapted for transporting children of different age ranges. In Europe, a system of groups has been established for categorizing child safety seats. This system ranges from “Group 0” seats suitable for newborn children via “Group 1”and “Group 2” seats up to “Group 3” seats suitable for children up to twelve years old. Besides the age of a child, other factors that have to be taken into account when choosing a child safety seat for a specific child include the weight and the height of the child.
In principle, a child safety seat can be mounted in a vehicle in one of two orientations: forward-facing, i.e. in such a way that a child positioned in the child safety seat faces the front of the vehicle carrying the child safety seat; or rear-facing, i.e. in such a way that a child positioned in the child safety seat faces the rear of the vehicle carrying the child safety seat. The present invention relates in particular to apparatuses for child safety seats configured for rear-facing installation in the vehicle. The present invention, however, is not limited to rear-facing child safety seats, it might as well be applied to forward-facing child safety seats.
The forces acting on a child sitting in a child safety seat during a crash of the vehicle carrying the child safety seat are influenced by the way the child safety seat is attached to the vehicle, i.e. by how the child safety seat is fixed to the vehicle seat it is placed on. Generally, there a two systems for fixing a child safety seat on a vehicle seat. The first system employs a seat belt provided in the vehicle for securing the child safety seat. In this system, at least one of the seat belts of the vehicle is guided in a prescribed way around or through the child safety seat thus securing the child safety seat in the desired position and orientation. An advantage of this system is that it exclusively makes use of fastening means that are usually present in every vehicle, i.e. the seat belts of the vehicle. Securing a child safety seat with a vehicle seat belt may, however, be cumbersome. Therefore, in practice, many child safety seats of this type are improperly installed in the vehicle. The second system employs fixing means which are provided in the vehicle specifically for securing a child safety seat. In Europe, the ISOFIX system has been introduced for this purpose. A vehicle seat adapted for installation of an ISOFIX child safety seat (i.e. a child safety seat equipped with the ISOFIX system) comprises anchors (ISOFIX anchors) which are provided at the lower end of the seat's seatback at the junction between the seat cushion and the seatback and which are fixedly attached to the seat. The ISOFIX child safety seat comprises connectors or latches (ISOFIX rigid latches) which can be coupled releasably to the anchors. Consequently, using the ISOFIX system a child safety seat can be easily and safely fixed to a vehicle seat. The child safety seat may furthermore comprise a Top Tether, a support leg, or a Rebound Bar, as an anti-rotation device.
The present invention relates in particular to apparatuses for ISOFIX child safety seats. The present invention, however, is not limited to ISOFIX child safety seats, it might as well be applied to other child safety seats having similar means for fixing the child safety seat to a vehicle seat.
In the following, illustrations and descriptions refer to rear-facing ISOFIX child safety seats, which is for reasons of simplicity only and does not limit the invention to apparatuses for rear-facing ISOFIX child safety seats only.
In a car crash involving a rear collision of the vehicle, a child safety seat is pushed towards the seatback of a seat of the vehicle. Due to that, rotary forces will act on the child safety seat, as the center of gravity of the child safety seat is located above the ISOFIX connectors attached to the ISOFIX anchoring points. Thus, the child safety seat will be rotated upwards, resulting in an increased risk of injury for the child in the child safety seat. Further, accelerating forces induced by the rear impact are directly transferred to the child safety seat and, thus, also to the child in the child safety seat.
As already mentioned above, a Rebound Bar may be used to inhibit such a rotation of the child safety seat. However, a Rebound Bar makes a child safety seat heavier and more unhandy, which is particularly disadvantageous when carrying a baby lying in the child safety seat to a vehicle.